12. Brachymenium ptychothecium (Besch.) Ochi 皱朔短月藓 zhou shuo duan yue xian
Advancing Frontiers Pl. Sci. 4: 108. 1963. Bryum ptychothecium Besch., Ann. Sci. Nat., Bot., ser. 7, 15: 66. 1892. Type: China. Yunnan, Mo-so-yn, Delav s.n.
Plants small to medium-sized, up to 15 mm high, pale brownish green to grayish green, in dense tufts. Stems erect, branched, densely foliate at apex, with dark brown rhizoids at base. Leaves appressed or twisted when dry, imbricate or slightly erect-spreading when moist, broadly ovate, clearly keeled or oblong-ovate to ligulate, acuminate, ca. 3–5 mm long; margins recurved throughout except near the apex, serrulate above, distinctly bordered by 3–6 rows of linear cells; costae shortly excurrent; median leaf cells elongate-hexagonal to rhomboidal, thick-walled, porose; basal cells larger, more or less thick-walled, rectangular to hexagonal. Autoicous. Setae straight or slightly curved, to 35 mm long; capsules inclined to horizontal, neck distinctly differentiated, shrunk when dry; exostome teeth linear-lanceolate, strongly papillose; endostome segments reduced; basal membrane yellowish or hyaline, papillose; cilia absent. Spores not seen.